Recent political reporting suggests that Republican leaders are in a state of high anxiety, trapped between an angry base that still views Obamacare as the moral equivalent of slavery and the reality that health reform is the law of the land and is going to happen.

But those leaders don’t deserve any sympathy. For one thing, that irrational base is a Frankenstein monster of their own creation. Beyond that, everything I’ve seen indicates that members of the Republican elite still don’t get the basics of health reform — and that this lack of understanding is in the process of turning into a major political liability.

On the unstoppability of Obamacare: We have this system in which Congress passes laws, the president signs them, and then they go into effect. The Affordable Care Act went through this process, and there is no legitimate way for Republicans to stop it.

Is there an illegitimate way? Well, the G.O.P. can try blackmail, either by threatening to shut down the government or, an even more extreme tactic, threatening not to raise the debt limit, which would force the United States government into default and risk financial chaos. And Republicans did somewhat successfully blackmail President Obama back in 2011.

However, that was then. They faced a president on the ropes after a stinging defeat in the midterm election, not a president triumphantly re-elected. Furthermore, even in 2011 Mr. Obama wouldn’t give ground on the essentials of health care reform, the signature achievement of his presidency. There’s no way he would undermine the reform at this late date.

Republican leaders seem to get this, even if the base doesn’t. What they don’t seem to get, however, is the integral nature of the reform. So let me help out by explaining, one more time, why Obamacare looks the way it does.

Start with the goal that almost everyone at least pretends to support: giving Americans with pre-existing medical conditions access to health insurance. Governments can, if they choose, require that insurance companies issue policies without regard to an individual’s medical history, “community rating,” and some states, including New York, have done just that. But we know what happens next: many healthy people don’t buy insurance, leaving a relatively bad risk pool, leading to high premiums that drive out even more healthy people.

To avoid this downward spiral, you need to induce healthy Americans to buy in; hence, the individual mandate, with a penalty for those who don’t purchase insurance. Finally, since buying insurance could be a hardship for lower-income Americans, you need subsidies to make insurance affordable for all.

So there you have it: health reform is a three-legged stool resting on community rating, individual mandates and subsidies. It requires all three legs.

But wait — hasn’t the administration delayed the employer mandate, which requires that large firms provide insurance to their employees? Yes, it has, and Republicans are trying to make it sound as if the employer mandate and the individual mandate are comparable. Some of them even seem to think that they can bully Mr. Obama into delaying the individual mandate too. But the individual mandate is an essential piece of the reform, which can’t and won’t be bargained away, while the employer mandate is a fairly minor add-on that arguably shouldn’t have been in the law to begin with.

I guess that after all the years of vilification it was predictable that Republican leaders would still fail to understand the principles behind health reform and that this would hamper their ability to craft an effective political response as the reform’s implementation draws near. But their rudest shock is yet to come. You see, this thing isn’t going to be the often-predicted “train wreck.” On the contrary, it’s going to work.

Oh, there will be problems, especially in states where Republican governors and legislators are doing all they can to sabotage the implementation. But the basic thrust of Obamacare is, as I’ve just explained, coherent and even fairly simple. Moreover, all the early indications are that the law will, in fact, give millions of Americans who currently lack access to health insurance the coverage they need, while giving millions more a big break in their health care costs. And because so many people will see clear benefits, health reform will prove irreversible.

This achievement will represent a huge defeat for the conservative agenda of weakening the safety net. And Republicans who deluded their supporters into believing that none of this would happen will probably pay a large personal price. But as I said, they have nobody but themselves to blame.